Association between Premastication and Diarrhoea in Infants: A Commentary
A paper by Conkle et al. focused on the role of behavioural-dietary aspects of diarrhoea–nutrition relationships and emphasized the association between prechewing and diarrhoea. Additionally, the paper demonstrated a statistically significant positive association between diarrhoea and ingestion of sweets and dairy foods, and a negative association between diarrhoea and not breastfeeding. A commentary by Habicht and Pelto published in the journal Maternal & Child Nutrition discussed the findings put forth by Conkle et al.
The focus on premastication as a negative practice and cause of child disease stems from the belief that exchanging saliva, with all its microbes, from a mother to an infant is disgusting and unhealthy. However, premastication also has a beneficial role in the development of infant immune systems, protection from illness, caries prevention and nutritional role in poor nutritional environments. Thus, stamping out premastication can be dangerous. In addition, from a policy perspective, stamping out premastication, without affecting the environment, would not reduce diarrhoea in infants.
The claim by Conkle et al. that premastication causes diarrhoea is less convincing as the influences of environmental factors posing as causal factors for diarrhoea are different in different kinds of environments. On the other hand, the authors propose that both the environment and premastication of the already contaminated foods are the causes of diarrhoea. Therefore, eliminating premastication would not reduce food pollution. Reverse causality is another story which maintains that premastication does not cause diarrhoea; instead it encourages mothers to premasticate as they believe it is good for children with diarrhoea.
The authors concur with Conkle et al. in the need for research to evaluate the epidemiological and other effects of encouraging and discouraging premastication. However, they conclude that various factors including other causes of diarrhoea, various outcomes of premastication, both detrimental and beneficial must be further evaluated.
News source - Habicht JP, Pelto GH. Addressing epidemiological and public health analytic challenges in outcome and impact research: a commentary on ‘Prechewing Infant Food, Consumption of Sweets and Dairy and Not Breastfeeding are Associated with Increased Diarrhoea Risk of Ten Month Old Infants’. Maternal & Child Nutrition. 2016 Jul;12(3):625-631.